It changes in whatever way it has to change so that when theta changes, a stays the same while b changes so that we keep a right triangle.

它按着既定的方式改变,因此当θ改变时，a保持不变，同时b改变,从而我们保持为直角三角形。

youdao

It changes in whatever way it has to change so that when theta changes, a stays the same while b changes so that we keep a right triangle.

它按着既定的方式改变,因此当θ改变时，a保持不变，同时b改变,从而我们保持为直角三角形。

youdao